As wireless communications technologies continue to evolve, the demands placed on radio frequency (RF) power amplifier (PA) circuitry used to amplify RF signals continue to dramatically increase. As a result of increasing RF signal frequencies as well as strict power, spectral masking, and bandwidth requirements, modern RF PAs are subjected to large amounts of stress over at least a portion of their operational parameters. That is, due to the ever increasing range of potential load impedances, RF signal frequencies, spectral masking requirements, environmental conditions, and supply voltages that may be encountered by RF PA circuitry, the likelihood of the device experiencing stress over at least a portion of these operational parameters is constantly growing. Many RF PAs are currently designed to avoid stress over the entirety of their operating parameters in order to increase the longevity of the RF PA. However, designing RF PA circuitry to avoid stress over all operating parameters often results in sub-optimal performance of the RF PA. Specifically, designing RF PA circuitry to avoid stress altogether requires designing the RF PA to operate without stress under the least ideal operating parameters, which may markedly decrease the performance of the RF PA when the operating parameters are not at their worst. Further, designing RF PA circuitry to avoid stress over all operating parameters is often very expensive.
Accordingly, there is a need for RF PA circuitry that is capable of avoiding stress that may damage or reduce the performance of the device and further that does not degrade the performance of the RF PA when the device is not under stress.